74 850 left me stranded

concours

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The ethanol is hygroscopic and combines with water. This is heavier than petrol / gasoline and sinks to the bottom. Unfortunately, if you decant off the water / ethanol mixture, you're left with petrol at a lower octane rating. The ethanol is a higher rating than the petrol and mixed to average out to the pump rating.
The first sentence is accurate. The second is inaccurate.
We no longer need to use this as a preventive measure:
1631563456266.png


As a bonus, our granchildren won't have rusty bottom seams in the gas tanks on the bikes they restore.
 

Onder

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They won't be restoring any motorbikes unless somebody comes up with some green fuel.
E10 is wot they flog in my zone now. I used to fear growing too feeble to kick start. Then I worried about being too feeble to ride. Now I think I may not be riding my old boat anchor because I cannot get fuel.
Don't laugh. Things are unwinding faster than we can imagine.
 

Mart UK

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The first sentence is accurate. The second is inaccurate.
We no longer need to use this as a preventive measure:
View attachment 81850

As a bonus, our granchildren won't have rusty bottom seams in the gas tanks on the bikes they restore.
I only know because I have an unheated garage that goes below dew point and I suffered condensation in a Triumph car fuel tank. You only need 0.4% of water in your fuel for phase separation of ethanol and water to occur. This then drops to the bottom of the tank.
See: Ethanol and Water Contamination: Results and Observations: F. John Hay, University of Nebraska:-
"This study showed the ten percent ethanol blend (E10) can hold 0.41 percent water or 3.06 teaspoons of water per
gallon. This amount would equal 0.625 pints of water per 20 gallon tank. Above this amount a
layer of ethanol water mix is formed and sinks to the bottom of the tank."
 
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I'll bet they could make a Norton "e-motor" replacement that could fit inside the hollowed out Norton engine cases! You could have a sound generator/speaker system that could select the appropriate sound - quiet neighborhood exhaust, on-the road exhaust, Isle of Man TT exhaust!

Nah...probably be much too trouble-free to be appealing! :)
 

Mart UK

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Be good if the sound box could electronically connect with the gear shift lever. Would also need a heat source, to drip oil onto, to get the right smell. But which oil would be best?
 

maylar

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OK guys, back on topic please.

All this talk about water and ethanol has me questioning my diagnosis of water in the gas.

A couple of additional data points -
- The gas was from a very busy local station that I use regularly, especially the 93 octane high test for my supercharged Buick. Never had a problem with it.
- When I drained the carb bowls I saw some dark wispy stuff swirling in the cup. Not particulate matter, just something odd.

So...

What we know - The bike started OK after a 30 minute ride on a flatbed truck. It would NOT start after sitting in my garage for 5 days. The carbs would tickle OK and the plugs were wet. After draining the bowls and tank and refilling with fresh gas, it fired right up and ran normally.

What we THINK we know - Whatever contaminate was in the gas settled to the bottom of the tank and would not ignite. OR, the gas cap vent doesn't work and I wasn't getting fuel. This seems unlikely however as the carbs would tickle and the plugs were wet.

Thoughts, please?
 
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I'll bet they could make a Norton "e-motor" replacement that could fit inside the hollowed out Norton engine cases! You could have a sound generator/speaker system that could select the appropriate sound - quiet neighborhood exhaust, on-the road exhaust, Isle of Man TT exhaust!

Nah...probably be much too trouble-free to be appealing! :)
You'd only need a headphone socket....
 

concours

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My thoughts are, no problem with gas, just coincidence.
Yes, we can still get "bad gas", but your initial problem occurred while underway with the same fuel that ran fine when you set out.
It restarted fine later on the same fuel.
They never just "heal themselves", but an intermittent problem can be so very misleading.
Keep testing. Try to recreate the problem. Did you wiggle the wires going into the timing case while it's running?
I had learned about, and seen it firsthand, the female "snap" connecters are VERY FAILURE PRONE. The rubber jacket holds them together. Mostly. Replacing them ALL proactively is a good insurance policy. In your case it may bear fruit (smoking gun) visually. Cheap way to rule out intermittent connections.

 

maylar

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Yes, I wiggled the wires going into the timing case with the engine running. And checked very carefully that the insulation was intact - I've had Boyer pickup wires wear through the insulation there before and short to ground. I'm very confident that the wiring is sound and my ignition switch is fine too.

Need to test the gas tank vent. It's about the only unknown remaining. ~SOMETHING~ is up with the fuel.

Thanks for the advice.
 
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